This is a very good book, perhaps even an excellent book. Professor Mackintosh is, interestingly, a well respected experimental psychologist who practices in the field of animal learning. His text, The Psychology of Animal Learning, is somewhat of a classic in the field. Thus, one wonders why Professor Mackintosh would take on the behemoth of the IQ ideology given his background. Indeed, the study of human intelligence is a subspecialty of psychology in its own right. I suspect Professor Mackintosh's motivation lies in the intellectual and academic challenge of this pursuit, and his resultant product reflects a true scholarly effort.